I think I might have got to the bottom of this. Having not driven the Bongo for a few weeks, I took it on a long drive over the weekend with no smell. However the steering wheel sounds like a rusty old bicycle wheel and feels heavier than normal. I'm going to take it to my mechanic friend to have a ...

Thanks for your reply.

I did have to top up the coolant a while back but
it's been consistent since. I think it is more noticeable when the fan is on, I'll check. Is the heater matrix expensive to replace?

I have a Bongo 2.5 Td 1995 which I bought last year from 321away. I've recently been getting a smell in the cab area which I would describe as like burnt or cooked onions. This happens intermittently and is only noticeable when the vehicle is stationary. A mechanic friend had a quick look around ...